Leadership experts and the public alike extol the virtues of transformational leaders - those who set out bold objectives and take risks to change the world. We tend to downplay 'transactional' leaders, whose goals are more modest, as mere managers.

As we think of power in the 21st century, we want to get away from the idea that power's always zero sum - my gain is your loss and vice versa. Power can also be positive sum, where your gain can be my gain.

As we think of power in the 21st century, we want to get away from the idea that power's always zero sum - my gain is your loss and vice versa. Power can also be positive sum, where your gain can be my gain.